FIG 3.

SFV capsid suppresses siRNA-induced RNAi. (A) 293T cells were cotransfected with a plasmid encoding EGFP (0.1 μg) and EGFP-specific siRNA (siEGFP) (50 nM), together with either empty plasmid or a plasmid encoding SFV capsid protein or NB2 (1 μg for each). At 48 hpt, the total RNAs were extracted for Northern blotting. GAPDH mRNA was used as the loading control. (B) Increasing amounts (0 to 8 μM) of MBP fusion capsid were incubated with 1 μM DIG-labeled synthetic 22-nt siRNA at 25°C for 30 min. Complexes were separated on 1.5% native-TBE agarose gel, transferred to membranes, and then incubated with anti-DIG antibody conjugated with alkaline phosphatase.